Stereo recording is performed using stereo microphones for which two microphones (hereinafter, also simply referred to as mics in some cases) are provided on the left and right. There is an effect that, for example, a sense of localization can be obtained by recording through stereo mics. However, since a distance between mics is short in a small-sized device like, for example, an IC recorder, a sense of localization cannot sufficiently be obtained in some cases.
Accordingly, directional mics are used for improving a sense of localization. For example, the following Patent Literature 1 discloses a technology that can adjust a sense of localization by adjusting an angle of two directional mics.